21. Which THREE of the following are true statements about the water cycle?
Answer: A,C,D
Clouds are formed when water vapor in the air changes into liquid water.
Clouds are indeed formed when water vapor in the air condenses into tiny droplets of liquid water. This process is a fundamental part of the water cycle, illustrating how water transitions between different states in the atmosphere.
A) Clouds are formed when water vapor in the air changes into liquid water.
This statement is correct, as it accurately describes the process of condensation, where water vapor cools and transforms into liquid droplets, forming clouds.
B) Rainfall results from a collision between two or more clouds in the atmosphere.
This statement is incorrect. Rainfall occurs when water droplets in clouds grow large enough to overcome air resistance and fall to the ground, not from the collision of clouds. Collisions may contribute to the growth of droplets, but they are not the primary cause of rainfall.
C) Some of the rain that falls to Earth becomes groundwater.
This statement is correct, as it reflects the process of infiltration, where rainwater seeps into the ground and replenishes aquifers, which are critical sources of groundwater.
D) Some water returns to the atmosphere by evaporating through plant leaves.
This statement is correct, as it describes transpiration, a process by which water is absorbed by plant roots and then released as vapor through leaves, contributing to the moisture in the atmosphere.
Conclusion
The correct statements about the water cycle—A, C, and D—accurately describe key processes such as condensation, infiltration, and transpiration. Option B fails to correctly explain the mechanism of rainfall, demonstrating a misunderstanding of the water cycle's dynamics.